According to the 2010 census, the county has a total area of 401.43 square miles (1,039.7 km2), of which 396.74 square miles (1,027.6 km2) (or 98.83%) is land and 4.68 square miles (12.1 km2) (or 1.17%) is water.[5]

In recent years, average temperatures in Rockport have ranged from a low of 24 °F (−4 °C) in January to a high of 91 °F (33 °C) in July, although a record low of −23 °F (−31 °C) was recorded in January 1994 and a record high of 107 °F (42 °C) was recorded in June 1944. Average monthly precipitation ranged from 3.01 inches (76 mm) in October to 4.78 inches (121 mm) in May.[6]

County Council: The county council is the legislative branch of the county government and controls all the spending and revenue collection in the county. Representatives are elected from county districts. The council members serve four-year terms. They are responsible for setting salaries, the annual budget, and special spending. The council also has limited authority to impose local taxes, in the form of an income and property tax that is subject to state level approval, excise taxes, and service taxes.[7][8]

Board of Commissioners: The executive body of the county is made of a board of commissioners. The commissioners are elected county-wide, in staggered terms, and each serves a four-year term. One of the commissioners, typically the most senior, serves as president. The commissioners are charged with executing the acts legislated by the council, collecting revenue, and managing the day-to-day functions of the county government.[7][8]

Court: The county maintains a small claims court that can handle some civil cases. The judge on the court is elected to a term of four years and must be a member of the Indiana Bar Association. The judge is assisted by a constable who is also elected to a four-year term. In some cases, court decisions can be appealed to the state level circuit court.[8]

County Officials: The county has several other elected offices, including sheriff, coroner, auditor, treasurer, recorder, surveyor, and circuit court clerk. Each of these elected officers serves a term of four years and oversees a different part of county government. Members elected to county government positions are required to declare party affiliations and to be residents of the county.[8]

As of the 2010 United States Census, there were 20,952 people, 8,082 households, and 5,907 families residing in the county.[14] The population density was 52.8 inhabitants per square mile (20.4/km2). There were 8,872 housing units at an average density of 22.4 per square mile (8.6/km2).[5] The racial makeup of the county was 96.9% white, 0.5% black or African American, 0.3% Asian, 0.2% American Indian, 1.3% from other races, and 0.8% from two or more races. Those of Hispanic or Latino origin made up 2.5% of the population.[14] In terms of ancestry, 47.0% were German, 16.4% were Irish, 12.6% were English, and 11.1% were American.[15]

Of the 8,082 households, 33.5% had children under the age of 18 living with them, 60.8% were married couples living together, 8.1% had a female householder with no husband present, 26.9% were non-families, and 23.2% of all households were made up of individuals. The average household size was 2.55 and the average family size was 3.00. The median age was 41.9 years.[14]

The median income for a household in the county was $47,697 and the median income for a family was $61,365. Males had a median income of $44,526 versus $30,466 for females. The per capita income for the county was $23,609. About 6.8% of families and 12.1% of the population were below the poverty line, including 18.0% of those under age 18 and 12.8% of those age 65 or over.[16]